[Contribution of intraperitoneal chemotherapy in the treatment of colorectal peritoneal carcinoma. HIPEC, PIPAC, state of the art and future directions]. / La chimiothérapie intra-péritonéale dans le traitement de la carcinose péritonéale d'origine colorectale. CHIP, PIPAC, état des lieux et perspectives.

After more than a decade of good results using the combination of cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) in the treatment of peritoneal carcinosis of colorectal origin, the PRODIGE7 study, which specifically evaluated the role of HIPEC, failed to show any superiority in terms of overall and disease-free survival for the CRS+HIPEC combination compared with CRS alone. This study constituted a radical change in the knowledge and therapeutic attitudes observed to date. After reviewing the literature and the consensus of national and international experts, a synthesis is provided, together with an outlook on the questions raised and the therapeutic trials and innovations of the near future. An analysis of recent advances due to the advent of a new technique, PIPAC, is also proposed, as well as a review of current therapeutic trials in this field.

Descriptive review of current practices and prognostic factors in patients with ovarian cancer treated by pressurized intraperitoneal aerosol chemotherapy (PIPAC): a multicentric, retrospective, cohort of 234 patients.

Introduction: Ovarian cancer (OC) is the primary cause of mortality in women diagnosed with gynecological cancer. Our study assessed pressurized intraperitoneal aerosol chemotherapy (PIPAC) as treatment for peritoneal surface metastases (PSM) from recurrent or progressive OC and conducted survival analyses to identify prognostic factors. Material and methods: This retrospective cohort study, conducted across 18 international centers, analyzed the clinical practices of patients receiving palliative treatment for PSM from OC who underwent PIPAC. All patients were initially treated appropriately outside any clinical trial setting. Feasibility, safety, and morbidity were evaluated along with objective endpoints of oncological response. Multivariate analysis identified prognostic factors for OS and PFS. Results: From 2015-2020, 234 consecutive patients were studied, from which 192 patients were included and stratified by platinum sensitivity for analysis. Patients with early recurrence, within one postoperative month, were excluded. Baseline characteristics were similar between the groups regarding platinum sensitivity (platinum sensitive (PS) and resistant (PR)), but chemotherapy frequency differed, as did PCI before PIPAC. Median PCI decreased in both groups after three cycles of PIPAC (PS 16 vs. 12, p < 0.001; PR 24 vs. 20, p = 0.009). Overall morbidity was 22%, with few severe complications (4-8%) or mortality (0-3%). Higher pathological response and longer OS (22 vs. 11m, p = 0.012) and PFS (12 vs. 7m, p = 0.033) were observed in the PS group. Multivariate analysis (OS/PFS) identified ascites (HR 4.02, p < 0.001/5.22, p < 0.001), positive cytology at first PIPAC (HR 3.91, p = 0.002/1.96, p = 0.035), and ≥ 3 PIPACs (HR 0.30, p = 0.002/0.48, p = 0.017) as independent prognostic factors of overall survival/progression-free survival. Conclusions: With low morbidity and mortality rates, PIPAC is a safe option for palliative treatment of advanced ovarian cancer. Promising results were observed after 3 PIPAC, which did improve the peritoneal burden. However, further research is needed to evaluate the potential role of PIPAC as an independent prognostic factor.

E-AHPBA-ESSO-ESSR Innsbruck consensus guidelines for preoperative liver function assessment before hepatectomy.

BACKGROUND: Posthepatectomy liver failure (PHLF) contributes significantly to morbidity and mortality after liver surgery. Standardized assessment of preoperative liver function is crucial to identify patients at risk. These European consensus guidelines provide guidance for preoperative patient assessment. METHODS: A modified Delphi approach was used to achieve consensus. The expert panel consisted of hepatobiliary surgeons, radiologists, nuclear medicine specialists, and hepatologists. The guideline process was supervised by a methodologist and reviewed by a patient representative. A systematic literature search was performed in PubMed/MEDLINE, the Cochrane library, and the WHO International Clinical Trials Registry. Evidence assessment and statement development followed Scottish Intercollegiate Guidelines Network methodology. RESULTS: Based on 271 publications covering 4 key areas, 21 statements (at least 85 per cent agreement) were produced (median level of evidence 2- to 2+). Only a few systematic reviews (2++) and one RCT (1+) were identified. Preoperative liver function assessment should be considered before complex resections, and in patients with suspected or known underlying liver disease, or chemotherapy-associated or drug-induced liver injury. Clinical assessment and blood-based scores reflecting liver function or portal hypertension (for example albumin/bilirubin, platelet count) aid in identifying risk of PHLF. Volumetry of the future liver remnant represents the foundation for assessment, and can be combined with indocyanine green clearance or LiMAx® according to local expertise and availability. Functional MRI and liver scintigraphy are alternatives, combining FLR volume and function in one examination. CONCLUSION: These guidelines reflect established methods to assess preoperative liver function and PHLF risk, and have uncovered evidence gaps of interest for future research.

Liver surgery is an effective treatment for liver tumours. Liver failure is a major problem in patients with a poor liver quality or having large operations. The treatment options for liver failure are limited, with high death rates. To estimate patient risk, assessing liver function before surgery is important. Many methods exist for this purpose, including functional, blood, and imaging tests. This guideline summarizes the available literature and expert opinions, and aids clinicians in planning safe liver surgery.

Current practice in assessment and management of malnutrition in surgical oncology practice - An ESSO-EYSAC snapshot analysis.

INTRODUCTION: Malnutrition is common in patients suffering from malignant diseases and has a major impact on patient outcomes. Prevention and early detection are crucial for effective treatment. This study aimed to investigate current international practice in the assessment and management of malnutrition in surgical oncology departments. MATERIAL AND METHODS: The survey was designed by European Society of Surgical Oncology (ESSO) and ESSO Young Surgeons and Alumni Club (EYSAC) Research Academy as an online questionnaire with 41 questions addressing three main areas: participant demographics, malnutrition assessment, and perioperative nutritional standards. The survey was distributed from October to November 2021 via emails, social media and the ESSO website to surgical networks focussing on surgical oncologists. Results were collected and analysed by an independent team. RESULTS: A total of 156 participants from 39 different countries answered the survey, reflecting a response rate of 1.4%. Surgeons reported treating a mean of 22.4 patients per month. 38% of all patients treated in surgical oncology departments were routinely screened for malnutrition. 52% of patients were perceived as being at risk for malnutrition. The most used screening tool was the "Malnutrition Universal Screening Tool" (MUST). 68% of participants agreed that the surgeon is responsible for assessing preoperative nutritional status. 49% of patients were routinely seen by dieticians. In cases of severe malnutrition, 56% considered postponing the operation. CONCLUSIONS: The reported rate of malnutrition screening by surgical oncologists is lower than expected (38%). This indicates a need for improved awareness of malnutrition in surgical oncology, and nutritional screening.

2022 PSOGI Consensus on HIPEC Regimens for Peritoneal Malignancies: Diffuse Malignant Peritoneal Mesothelioma.

BACKGROUND: Diffuse malignant peritoneal mesothelioma (DMPM) is a rare and aggressive primary peritoneal disease, with recommended treatment, in eligible patients, of a combination of complete cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). As treatment is multimodal, there is a wide heterogeneity of HIPEC protocols precluding clear comparisons. Standardization at an international level is required. METHODS: The Peritoneal Surface Oncology Group International (PSOGI) designated a steering committee to produce consensus recommendations for HIPEC regimens, adapted to each etiology. The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology was used, based on a systematic review focused on main outcomes related to HIPEC regimens in DMPM patients and on the patient, intervention, comparator, and outcome (PICO) method to elaborate main questions. An opinion survey was added. Furthermore, a Delphi process was performed with voting from a panel of international experts. RESULTS: Eleven questions were elaborated, including two for future research requirements and three to assess the HIPEC regimen preference of the panel. The level of evidence underlying questions was globally low. Overall, 75 (86%) and 67 (77%) of the 87 invited experts completed the vote at the first and second round, respectively. HIPEC following complete CRS was strongly supported by 88% of voters with no need to plan comparative studies with CRS alone for 61.2% of voters. Bi-drug regimens appeared to be preferred to mono-drug ones and cisplatin was globally favored. The opinion survey confirmed the combination of cisplatin and doxorubicin as the recommended regimen. CONCLUSION: International consensus confirmed the indication of HIPEC following complete CRS in DMPM patients and recommended cisplatin-doxorubicin as the first-line HIPEC regimen.

Peritoneal Mesothelioma: Systematic Review of Hyperthermic Intraperitoneal Chemotherapy (HIPEC) Protocol Outcomes.

Diffuse malignant peritoneal mesothelioma (DMPM) prognosis was improved by the locoregional treatment combining cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). HIPEC is a multiparametric treatment with multiple protocols proposed and reviewed in this work. A systematic review of medical literature was performed according to PRISMA guidelines. The search strategy used "malignant peritoneal mesothelioma" and "HIPEC" as keywords in three databases. Studies were included if reporting precisely the HIPEC regimen and the related outcomes, if comparing regimen, or if reporting national/international guidelines. The GRADE methodology was used to rate the level of evidence. Twenty-eight studies were included in this review: 1 was a meta-analysis, 18 reported cohort outcomes, 4 retrospectively compared HIPEC regimens, and 5 were guidelines. Six HIPEC regimens were found, 4 with one drug (cisplatin, mitomycine-C, carboplatin, oxaliplatin), 2 using two drugs (cisplatin-doxorubicin or cisplatin-mitomycine-C). Cisplatin, up to 250 mg/m2 over 90 min, appeared as the key HIPEC drug with a toxicity profile well controlled by the concomitant intravenous perfusion of sodium thiosulfate. Comparative studies tended to show that a bi-drug regimen led to better long-term oncologic outcomes, with cisplatin 50 mg/m2 plus doxorubicin 15 mg/m2 being safe and more efficient. This late protocol was the most widely used and recommended in 3 out of 4 international guidelines. Cisplatin was the preferred drug for HIPEC in DMPM patients. Most of the time, it was combined with doxorubicin for 90 min. A harmonization of protocols and further comparative studies are needed to optimize HIPEC regimen choice.

A prediction model to refine the timing of an early second-look laparoscopic exploration in patients with colon cancer at high risk of early peritoneal metastasis recurrence.

BACKGROUND: In patients at high risk of peritoneal metastasis (PM) recurrence following surgical treatment of colon cancer (CC), second-look laparoscopic exploration (SLLE) is mandatory; however, the best timing is unknown. We created a tool to refine the timing of early SLLE in patients at high risk of PM recurrence. METHODS: This international cohort study included patients who underwent CC surgery between 2009 and 2020. All patients had PM recurrence. Factors associated with PM-free survival (PMFS) were assessed using Cox regression. The primary endpoint was early PM recurrence defined as a PMFS of <6 months. A model (logistic regression) was fitted and corrected using bootstrap. RESULTS: In total, 235 patients were included. The median PMFS was 13 (IQR, 8-22) months, and 15.7% of the patients experienced an early PM recurrence. Synchronous limited PM and/or ovarian metastasis (hazard ratio [HR]: 2.50; 95% confidence interval [CI]: [1.66-3.78]; p < 0.001) were associated with a very high-risk status requiring SLLE. T4 (HR: 1.47; 95% CI: [1.03-2.11]; p = 0.036), transverse tumor localization (HR: 0.35; 95% CI: [0.17-0.69]; p = 0.002), emergency surgery (HR: 2.06; 95% CI: [1.36-3.13]; p < 0.001), mucinous subtype (HR: 0.50; 95% CI [0.30, 0.82]; p = 0.006), microsatellite instability (HR: 2.29; 95% CI [1.06, 4.93]; p = 0.036), KRAS mutation (HR: 1.78; 95% CI: [1.24-2.55]; p = 0.002), and complete protocol of adjuvant chemotherapy (HR: 0.93; 95% CI: [0.89-0.96]; p < 0.001) were also prognostic factors for PMFS. Thus, a model was fitted (area under the curve: 0.87; 95% CI: [0.82-0.92]) for prediction, and a cutoff of 150 points was identified to classify patients at high risk of early PM recurrence. CONCLUSION: Using a nomogram, eight prognostic factors were identified to select patients at high risk for early PM recurrence objectively. Patients reaching 150 points could benefit from an early SLLE.

Prevention of post-hepatectomy liver failure after major resection of colorectal liver metastases: is hepato-biliary scintigraphy the optimal tool?

Background: Liver failure is the most threatening complication after hepatectomy for colorectal liver metastases. Recent studies indicate that liver functional evaluation by hepatobiliary scintigraphy (HBS) could be more sensitive than volumetry to predict the risk of post-hepatectomy liver failure (PHLF). The aim of this study was to evaluate the performance of 99mTc-mebrofenin HBS, when used as the main preoperative assessment before major hepatectomy in patients with liver metastases from colorectal cancer. Methods: This retrospective study reviewed data from all patients with colorectal liver metastases treated at Montpellier Cancer Institute between 2013 and 2020. Only patients who underwent HBS before surgery were included. The primary aim was to evaluate how the use of this functional imaging modifies the surgical management of patients with colorectal liver metastases. Results: Among the 80 patients included, 26 (32.5%) underwent two-stage hepatectomy and 13 (16.3%) repeated hepatectomies. Severe postoperative complications occurred in 16 patients (20%) and all-grade liver failure occurred in 13 patients (16.3%). Seventeen patients (21.3%) underwent major liver surgery based on sufficient mebrofenin uptake, although the retrospectively evaluated future liver remnant (FLR) volume was insufficient (<30% of total liver). None of these patients had PHLF. Conclusions: This study showed the reliability of HBS for the preoperative functional assessment of patients with colorectal liver metastases. Indeed, it allowed performing major hepatectomy safely in 20% more patients who would not have been considered for surgery on the basis of volumetric assessment.

Perioperative chemotherapy in colorectal cancer with peritoneal metastases: A global propensity score matched study.

Background: There is a paucity of studies evaluating perioperative systemic chemotherapy in conjunction with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with colorectal cancer peritoneal metastases (CRCPM). The aim was to evaluate neoadjuvant and/or adjuvant systemic therapy in CRCPM. Methods: Patients with CRCPM from 39 treatment centres globally from January 1, 1991, to December 31, 2018, who underwent CRS+HIPEC were identified and stratified according to neoadjuvant/adjuvant use. Crude data analysis, propensity score matching (PSM) and Cox-proportional hazard modelling was performed. Findings: Of 2093 patients, 1613 were included in neoadjuvant crude evaluation with 708 in the PSM cohort (354 patients/arm). In the adjuvant evaluation, 1176 patients were included in the crude cohort with 778 in the PSM cohort (389 patients/arm). The median overall survival (OS) in the PSM cohort receiving no neoadjuvant vs neoadjuvant therapy was 37.0 months (95% CI: 32.6-42.7) vs 34.7 months (95% CI: 31.2-38.8, HR 1.08 95% CI: 0.88-1.32, p = 0.46). The median OS in the PSM cohort receiving no adjuvant therapy vs adjuvant therapy was 37.0 months (95% CI: 32.9-41.8) vs 45.7 months (95% CI: 38.8-56.2, HR 0.79 95% CI: 0.64-0.97, p = 0.022). Recurrence-free survival did not differ in the neoadjuvant evaluation but differed in the adjuvant evaluation - HR 1.04 (95% CI: 0.87-1.25, p = 0.66) and 0.83 (95% CI: 0.70-0.98, p = 0.03), respectively. Multivariable Cox-proportional hazard modelling in the crude cohorts showed hazard ratio 1.08 (95% CI: 0.92-1.26, p = 0.37) for administering neoadjuvant therapy and 0.86 (95% CI: 0.72-1.03, p = 0.095) for administering adjuvant therapy. Interpretation: Neoadjuvant therapy did not confer a benefit to patients undergoing CRS+HIPEC for CRCPM, whereas adjuvant therapy was associated with a benefit in this retrospective setting. Funding: None.

The landscape of cancer-associated fibroblasts in colorectal cancer liver metastases.

Rationale: Patients with colorectal cancer die mainly due to liver metastases (CRC-LM). Although the tumor microenvironment (TME) plays an important role in tumor development and therapeutic response, our understanding of the individual TME components, especially cancer-associated fibroblasts (CAFs), remains limited. Methods: We analyzed CRC-LM CAFs and cancer cells by single-cell transcriptomics and used bioinformatics for data analysis and integration with related available single-cell and bulk transcriptomic datasets. We validated key findings by RT-qPCR, western blotting, and immunofluorescence. Results: By single-cell transcriptomic analysis of 4,397 CAFs from six CRC-LM samples, we identified two main CAF populations, contractile CAFs and extracellular matrix (ECM)-remodeling/pro-angiogenic CAFs, and four subpopulations with distinct phenotypes. We found that ECM-remodeling/pro-angiogenic CAFs derive from portal resident fibroblasts. They associate with areas of strong desmoplastic reaction and Wnt signaling in low-proliferating tumor cells engulfed in a stiff extracellular matrix. By integrating public single-cell primary liver tumor data, we propose a model to explain how different liver malignancies recruit CAFs of different origins to this organ. Lastly, we found that LTBP2 plays an important role in modulating collagen biosynthesis, ECM organization, and adhesion pathways. We developed fully human antibodies against LTBP2 that depleted LTBP2+ CAFs in vitro. Conclusion: This study complements recent reports on CRC-LM CAF heterogeneity at the single-cell resolution. The number of sequenced CAFs was more than one order of magnitude larger compared to existing data. LTBP2 targeting by antibodies might create opportunities to deplete ECM-remodeling CAFs in CRC-LMs. This might be combined with other therapies, e.g., anti-angiogenic compounds as already done in CRC. Moreover, we showed that in intrahepatic cholangiocarcinoma, in which ECM-remodeling CAF proportion is similar to that of CRC-LM, several genes expressed by ECM-remodeling CAFs, such as LTBP2, were associated with survival.

Assessment of Treatment Response after Pressurized Intra-Peritoneal Aerosol Chemotherapy (PIPAC) for Appendiceal Peritoneal Metastases.

Background The aim of this study was to analyse survival and surrogates for oncological response after PIPAC for appendiceal tumours. Methods This retrospective cohort study included consecutive patients with appendiceal peritoneal metastases (PM) treated in experienced PIPAC centers. Primary outcome measure was overall survival (OS) from the date of diagnosis of PM and from the start of PIPAC. Predefined secondary outcome included radiological response (RECIST criteria), repeat laparoscopy and peritoneal cancer index (PCI), histological response assessed by the Peritoneal regression grading system (PRGS) and clinical response. Results Final analysis included 77 consecutive patients (208 PIPAC procedures) from 15 centres. Median OS was 30 months (23.00-46.00) from time of diagnosis and 19 months (13.00-28.00) from start of PIPAC. 35/77 patients (45%) had ≥3 procedures (pp: per protocol). Objective response at PIPAC3 was as follows: RECIST: complete response 4 (11.4%), 11 (31.4%) partial/stable; mean PRGS at PIPAC3: 1.8 ± 0.9. Median PCI: 21 (IQR 18-27) vs. 22 (IQR 17-28) at baseline (p = 0.59); 21 (60%) and 18 (51%) patients were symptomatic at baseline and PIPAC3, respectively (p = 0.873). Median OS in the pp cohort was 22.00 months (19.00-NA) from 1st PIPAC. Conclusion Patients with PM of appendiceal origin had objective treatment response after PIPAC and encouraging survival curves call for further prospective evaluation.

The BUMPy road of peritoneal metastases in ovarian cancer.

Ovarian cancer is the most common cause of death due to gynecologic malignancies, with more than 70% of patients presenting with advanced stage disease at the time of diagnosis. The extent and distribution of tumor guide primary treatment selection and clinical management. While primary cytoreductive surgery with complete tumor resection improves survival, patients with extensive peritoneal disease may benefit from neoadjuvant chemotherapy first to reduce tumor burden followed by interval cytoreductive surgery. Imaging plays an essential role in triaging patients including selecting patients who may benefit from neoadjuvant chemotherapy before cytoreductive surgery. Interestingly, there are no universally established criteria to predict resectability and local practices depend on local guidelines and surgeon preferences. Nevertheless, certain anatomical tumor locations are known to be difficult to resect and are associated with suboptimal cytoreduction or require special surgical considerations. This review discusses the recent advances in the initial management of patients with ovarian cancer, a practical approach to the assessment and communication of peritoneal metastases locations on CT and MRI. It also explores recent advances in genomics profiling and radiomics that may influence the initial management of these patients.

The desmoplastic growth pattern is associated with second-stage completion and longer survival in 2-stage hepatectomy for colorectal cancer liver metastases.

BACKGROUND: Two-stage hepatectomy for bilobar colorectal cancer liver metastases is potentially curative for selected patients. Histological growth patterns of colorectal liver metastases (desmoplastic, replacement, and pushing) have prognostic value. Our aim was to evaluate their association with pathologic response to preoperative treatment, second-stage hepatectomy completion, and survival in patients treated with a curative-intent 2-stage hepatectomy. METHODS: In 67 patients planned for 2-stage hepatectomy, colorectal liver metastases resected from the first-stage hepatectomy were retrospectively evaluated for growth patterns and pathologic response according to Tumor Regression Grading, modified Tumor Regression Grading, and Blazer grading. Tumor Regression Grading 1 to 3, modified Tumor Regression Grading 1 to 3, and Blazer 0 and 1 defined good responders. RESULTS: Desmoplastic growth patterns (GP) were more frequent among good responders (P < .001). Second-stage hepatectomy completion was associated with desmoplastic growth patterns and pathologic response on univariate analysis and multivariable analyses (P = .017 and P = .041, respectively). Median follow-up was 84 months (95% confidence interval: 53.4 [not reached]). Nondesmoplastic GP patients and nonresponders had a poorer overall survival (hazard ratio = 3.86, 95% confidence interval: 2.11-7.07, P < .001 and hazard ratio = 2.14, 95% confidence interval: 1.19-3.83, P = .009, respectively) on univariate analysis. Nondesmoplastic growth pattern was the only factor associated with a poorer overall survival on multivariable analysis (hazard ratio = 4.17, 95% confidence interval: 1.79-9.74, P < .001). Nondesmoplastic GP was also associated with a poorer recurrence-free survival (hazard ratio = 2.05, 95% confidence interval: 1.13-3.70, P = .017). CONCLUSION: Desmoplastic GP could represent a useful morphological marker for early identification of patients who might benefit from 2-stage hepatectomy completion.

Feasibility and safety of PIPAC combined with additional surgical procedures: PLUS study.

BACKGROUND: PIPAC (Pressurized IntraPeritoneal Aerosol Chemotherapy) is a minimally invasive approach relying on physical principles for improving intraperitoneal drug delivery, including optimizing the homogeneity of drug distribution through an aerosol. Feasibility and safety of the new approach are now consolidated and data on its effectiveness are continuously increasing. Although any surgical procedure associated with PIPAC had always been discouraged due to the high risk of complications, surgical practice is constantly changing: with growing expertise, more and more surgical teams associate PIPAC with surgery. METHODS: PLUS study is part of the retrospective international cohort studies including 10 centers around the world (India, Italy, France, Germany, Belgium, Russia, Saudi Arabia, Switzerland) and 96 cases of combined approaches evaluated through a propensity score analysis. RESULTS: the procedures most frequently associated with PIPAC were not only adhesiolysis, omentectomy, adnexectomy, umbilical/inguinal hernia repairs, but also more demanding procedures such as intestinal resections, gastrectomy, splenectomy, bowel repair/stoma creation. Although the evidence is currently limited, PLUS study demonstrated that PIPAC associated with additional surgical procedures is linked to an increase of surgical time (p < 0.001), length of stay (p < 0.001) and medical complication rate (p < 0.001); the most frequently reported medical complications were mild or moderate in severity, such as abdominal pain, nausea, ileus and hyperthermia. No difference in terms of surgical complications was registered; neither reoperation or postoperative deaths were reported. CONCLUSIONS: these results suggest that PIPAC can be safely combined in expert centers with additional surgeries. Widespread change of practice should be discouraged before the results of ongoing prospective studies are available.

Selection Criteria for Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) Treatment in Patients with Peritoneal Metastases.

Background: The standard treatment protocol for PIPAC consists of three procedures. Completion of treatment has been shown to be prognostic of improved survival. The aim of this study was to identify predictors for completion of treatment. Methods: Retrospective multicentric cohort study of patients with peritoneal metastases undergoing PIPAC in three PIPAC expert centers. Per protocol (PP) treatment was defined as patients receiving ≥3 PIPACs and was compared to patients receiving <3. Results: Overall, 183 patients had 517 PIPACs. The main reasons for stopping PIPAC were disease progression in 50% patients, bowel obstruction in 15%, patient's refusal to pursue in 10%, conversion to cytoreductive surgery in 7%, and medical reasons in 8%. Overall, 95 patients (52%) had PP treatment. The PP median OS was 17 vs. 7 months, p = 0.001. PP patients had r ascites (410 ± 100 mL vs. 960 ± 188 mL, p = 0.001), no prior history of bowel obstruction (12% vs. 24%, p = 0.028), and more bimodal treatment (39% vs. 13%, p < 0.001). After multiple regression, bimodal treatment was found as an independent predictive factor for completing PP (OR = 4.202, 95%CI [1.813, 10.630], p < 0.001), along with prior bowel obstruction (OR = 0.389, 95%CI [0.153, 0.920], p = 0.037). Conclusion: The absence of ascites and prior bowel obstruction can help to select patients suitable for PIPAC. Best results seem to be achieved when PIPAC is combined with systemic chemotherapy.

Consensus statement for treatment protocols in pressurized intraperitoneal aerosol chemotherapy (PIPAC).

Objectives: Safe implementation and thorough evaluation of new treatments require prospective data monitoring and standardization of treatments. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a promising alternative for the treatment of patients with peritoneal disease with an increasing number of suggested drug regimens. The aim was to reach expert consensus on current PIPAC treatment protocols and to define the most important research topics. Methods: The expert panel included the most active PIPAC centers, organizers of PIPAC courses and principal investigators of prospective studies on PIPAC. A comprehensive literature review served as base for a two-day hybrid consensus meeting which was accompanied by a modified three-round Delphi process. Consensus bar was set at 70% for combined (strong and weak) positive or negative votes according to GRADE. Research questions were prioritized from 0 to 10 (highest importance). Results: Twenty-two out of 26 invited experts completed the entire consensus process. Consensus was reached for 10/10 final questions. The combination of doxorubicin (2.1 mg/m2) and cisplatin (10.5 mg/m2) was endorsed by 20/22 experts (90.9%). 16/22 (72.7%) supported oxaliplatin at 120 with potential reduction to 90 mg/m2 (frail patients), and 77.2% suggested PIPAC-Ox in combination with 5-FU. Mitomycin-C and Nab-paclitaxel were favoured as alternative regimens. The most important research questions concerned PIPAC conditions (n=3), standard (n=4) and alternative regimens (n=5) and efficacy of PIPAC treatment (n=2); 8/14 were given a priority of ≥8/10. Conclusions: The current consensus should help to limit heterogeneity of treatment protocols but underlines the utmost importance of further research.